P. W. Bridgman and the Special Theory oj Relativity Ey W. Bridgman wrote A S,phi,ticati< him" (1962) for the reader "who feels the need to stand back a little for a critical scrutiny of what he has really got" (SP, p. 3). * This was his personal trademark as physicist and philoso pher and it is present everywhere in Bridgman's precis of special relativity theory. The reissue of Sophisticate's Primer is particularly wel come for it exhibits a quest for clarity in foundations in the style of Ernst Mach and Henri Poincare, in whose philo- N.B. Papers and books are here cited as follows. Bridgman (1927) refers to Bridgman's book The Logic of Modern Physics in the bibliography. Cross-references to Sophisticate's Primer are indicated with the code (SP, p. "'). Bridgman's extant manuscripts are on deposit at the Harvard University Archives, and here cited by date, for example (MS 2 August 1959, p .... ). Some of the manuscripts were written over a period of days, with sequential paging, with the actual dates indicated. Full citations are given in the bibliography. I am grateful to the Harvard University Archives for permission to quote from these materials, and to Bridgman's daughter, Mrs. Jane Koopman, for permitting me to quote from the draft manuscripts of Sophisticate's Primer, which will be deposited in the Harvard Archives. Reprinted from P. W. Bridgman. Sophisticate's Primer of Relativity, Second Edition. Middletown, CT: Wesleyan University Press, 1983.